Senior Data Scientist — Fraud & Risk ML, Stock Options

ARQ; Greater London; On-site; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Competitive salary and benefits

Stock options

Discretionary performance bonus

In-office collaboration

Latest tools and technology

Job summary

ARQ is seeking a Senior Data Scientist to help build the intelligence layer behind ARQ's financial products. You will design, develop, and deploy ML models to detect fraud, reduce losses, and scale risk management across the business.

In this role you will transform complex financial crime challenges into production-ready solutions, partnering with Product, Engineering, and Operations to deliver measurable impact for millions of customers.

Qualifications

• 5+ years of experience across Data Science, Machine Learning, Software Engineering, or related disciplines.
• Strong Python skills and experience with large-scale datasets.
• Proven experience developing and deploying machine learning models in production.
• Strong understanding of supervised learning techniques, particularly classification.
• Experience with anomaly detection, fraud prevention, risk modeling, or related domains.
• Ability to translate business challenges into data-driven solutions.
• Experience working cross-functionally with Product, Engineering, and business stakeholders.
• Strong communication skills and a pragmatic approach to problem-solving.
• Comfortable operating in fast-moving environments with high ownership.

Responsibilities

• Design, build, and deploy machine learning models that solve real-world financial crime and risk challenges.
• Work on problems such as fraud detection, chargeback prediction, anomaly detection, identity verification, and transaction monitoring.
• Transform ambiguous business problems into measurable ML solutions.
• Partner closely with Product and Operations teams to define requirements, success metrics, and decision frameworks.
• Analyse large datasets to identify patterns, opportunities, and risks.
• Build and maintain production-ready data pipelines and model-serving solutions.
• Monitor model performance and continuously improve accuracy, reliability, and business impact.
• Collaborate with Data Engineering and Backend Engineering teams to operationalise machine learning at scale.
• Help shape the future of AI and machine learning capabilities across ARQ.

Skills

5+ years experience

Python

Production ML

Supervised learning

Anomaly detection / fraud prevention

Cross-functional collaboration

Communication skills

Problem solving

Job description

ARQ is seeking a Senior Data Scientist to help build the intelligence layer behind ARQ's financial products. You will design, develop, and deploy ML models to detect fraud, reduce losses, and scale risk management across the business.

In this role you will transform complex financial crime challenges into production-ready solutions, partnering with Product, Engineering, and Operations to deliver measurable impact for millions of customers.